Method of making decolorizing materials.



R. M. CATLIN.

METHOD 0F MAKING DECOLORIZING MATERIALS.

APPLICATION FILED APR. 25,1916.

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EOBERTM. CATLIN, 0E FRANKLIN' FURNACE, NEW JEEsEY.v

METHOD OF MAKING DECOLORIZING- MATERIALS.

' Specification of Letters Patent.

Patented Mar. 20, 1917.

application mea 111111125, 1916. seriaiNo. 93,414.

To all whom t may concern.'

Be it known that I', ROBERT M. CATLIN, a citizen of the United States,residing at Franklin Furnace, county of Sussex, and State of NewJersey','have invented certain new and useful `Improvements' in Methodsof Making Decolorizing Materials, fully described and represented in thefollowing vspecification and the accompanying drawings, forming a partof the same.

This invention relates to a method ofmaking a material having a highdecolorizing power. Y y

The object of the invention is to provide a process by which there maybe produced a product-having a relatively high decolorizing power, whichproduct can be manufac- 'tured in flarge quantities at areasonableprice.

The invention will. be described in connec tion with the accompanyingdrawings, which show an apparatus suitable for carrying out the processin a commercial way. v

In the di-awing's* Figure l is a diagrammatic side view, and

- Fig. 2 is a diagrammatic planview.

In the best embodiment of the new process, the starting material is acertain residue obtained from thev distillatipn of shale, thisdistillation being carried out for 1 gether with small amounts'oi otheringre- I clients, such iron, magnesium and calcium.

One such shale residue, which may be cited as typical, gave thefollowing analysis:

S102 i 58.53 Fe203 9.01 Alzo,4 v8.43 Mg() .53 CaO 1.05 G 21.14.

In carrying out theprocess to produce the o "new decolorizing material,the starting mathe water to a second settling tank, where it 1s allowedto settle.

The fine material obtained as above dei colorizing power upon the solidsremaining,

which constitute the final product. From a series of experiments made byme, the decolorizing power seems to be so proportioned.

to the amount of product obtained from the starting material as toindicate that itis not due wholly to the decolorizing .powerof thecarbon alone. For example, analysis of some typical products show thatthe constituents are chiefly carbon and silica. The amount of' silicapresent in the final product seems to be determined by the amount ofhydrofluoric acid used in treating the starting material and theconditions under which said material was treated, as, for example,

the temperature and the amount of agitation. A

By controlling this treatment, the amount of material other than carbonin proportion to the carbon may be varied, so that the final product mayconstitute any desired proportion of the original starting material. It'the decolorizing power of the final product were due only to the carbonin such product, the power would be in proportion to such carbon. Myexperiments have shown that this is not the fact, and that thedecolorizing power of the final product seems to be such that it, can becalculated. approximately by assuming that the carbon present has adecolorizing power of between 80 and 90, and that all the othermaterials accompanying the carbon have ay decolorizing power of between60 vand 80. A series of products produced by me have shown delcolorizingpowers which could be calculated approximately by assumingv adecolorizing power of the carbon of about 90 and of all the othermaterials of' about 70. Consequently, it is found that only a relativelysmal-l amount of hydrofluoric acid may be vemployed in treating thestarting materials,

and that a product maybe obtained which is a relatively large proportionof the starting material, while at the same time the decolorizing poweris relatively high.

It has been found that the degree of concentration of the acid and thetotal amount of hydrouoric acid relatively to the amount of startingvmaterial, materially affects the nature, and also the quantity, of theresultant product. The less the amount of acid in proportion to thestarting material, the greater will be the quantity of thedecolori'zing-inaterial" obtained, and, of course, its decolorizingpower willbe lower', v'but will vstill hel high 'enough for commercialpurposes. Of course, if the treatment with acid is so slight as todissolveibut little silica,'the

proportion of the final product to the starting material may bevery'large, but the decolorizing power will not be 'sufliciently de-'veloped The decolorizing' power of the hydrofluoric acid, used so thatthe proportion of hydroluoric 1 acidv to the starting material was thesame as before, gave a productamountmg to about 56.3% by Weight of thelstarting material, with a decolori'zing power of about 74.2.

.The amount of acid to be used in proportion to they startingmaterial'is dependent upon the amount of product which it is desired toobtain relatively to the starting material. p

The time of the reaction depends upon the temperature of the solution,since a hot solution will generally react more rapidly than a coldsolution. Furthermore, it has .been found that agitation in any suitableway increases the rapidity of the reaction.

Upon the'completion of the reaction, the solids of the mixture arewashed thoroughly to 'free them from any soluble luorids or freehydroflluoric or hydrofluosilicic a/ci ds. If desired, the solids ma" beseparated from the'liquid in any suita le way, as by filtration orsettling and decantation, and then washedwith water. However, incarrying out 'the process commercially, it is better to displace theliquids by supplying washwater directly to the mixture' of solids andliquids, at the end lof thel reaction,` and thereby gradually wash awayfrom the solids the 'soluble matters and any remain-A ing acid. Thesolids are then settled out from the wash-water and separated from anyaccompanying liquid by filtration. The solids thus obtained are readyfor the market.

The product as above obtained is an eX- cellent decolorizer and,onraccount of its low cost of production, has an extensive applicationin the arts.

While it will vary somewhat in composition according to the nature ofthe starting.

material from which it is made, its chief in-Y gredients seem to becarbon and silica, the latter. apparently being in some form whichassists the carbon in thedecolorizing action. A typical product made ashereinbefore described, with a 16% solution of 'HF from a startingmaterial of the type referred to hereinabove, gave the followinganalysis:

C 42.97 S102; 520i Other constituents in traces 4. 9S)

The decolorizing power of this particular product was 79.6. YVhen thisproduct was burned, the remaining ash amounted to 57% by weight of theoriginal product.

rlhe material, of course, gradually. loses its decolorizing power withuse, but may be readily regenerated in any suitable way, as, forexample, by heating without access of air, or preferably by subjectingit again to the action of hydrofluoric acid, and then l In this drawing,A indicates any suitable f retort furnace by which s hale may be heatedto drive off the hydrocarbons which it contains. The shale residues aredischarged from the furnace vinto a suitable receptacle, a as, forexample, a hopper tank B to the bottom of which is connected a suitablegrinder and pump, as indicated at C, which serves to grind the materialand also to pump it through a discharge pipe c mto the top of a settlingtank for settling coarse material. This is a conical tank, as indicatedat D. It has its top arranged at a higher level than the top of thehopper tank B, and its bottom is connected to a pipe d arranged todischarge into the top of the hopper tank B. Furthermore, the coarsesettling tank D has'an overflow conduit d arran ed to discharge' into aconical settling tank which serves to settle fine material. This finesettling tank has an overflow e which may lead back tothe top of thehopper tank Band also'has a bottomy discharge to which is connected amovable discharge pipeY e controlled by a valve e2. Thispipe may be soarranged that. i-ts outer end may be moved to discharge ,into either oneof two mixing tanks F, F2.

The apparatus comprising the grinder pump C, the tanks B, D and E, andthe various connections constitute means for producing a nely comminutedmaterial. The. settling tanks D and E are advantageously of the typeshown, in which the ma terial supplied to each tank is admitted to thecentral upper portion, and suitable protecting cylinders surround theinlet to minimize the disturbing influence of the inflowing material onthe body of the liquid in the tank. lVater is supplied to thiscomminuting and grading apparatus at any suitable point, as, forexample, thro-ugh an inlet pipe e3 leading to the tank E. The shalerefuse, dropped from the retort into the water in the tank B, is alreadyin a condition where it may be acted upon by the combined grinder andpump.

By this apparatus it is broken up and then pumped to the coarse settlingtank D. Here the coarse material settles and is returned to the tank B.The fine material is carried ofi by the outflowing water to the finesettling tank E, where the fine material settles to the bottom and isdischarged into the particular mixing tank F or F, with which thedischarge e at that time communicates.

By means of the o'vrfiow c at the top of the fine settling tank E, thewater drawn from the tank B by the grinder pump C is continuouslyreturned to said tank B. The water supply to the tank E through thesupply pipe e3 is so adjusted that it will maintain the level of liquidin the tank E at the desired height.

The mixing tanks are intended to be used alternately. Each is provided"with suitable means for agitating materials therein. In the presentexample, this agitating means is shown as stirrers, one for each tank,each stirrer G having -a vertical shaft with a drive wheel g at itsupper end, to which power may be applied to drive the agitator.

lVhen one of the mixing tanks (F or F2) is filled, the dischargev pipe eis shifted to the other tank. The agitator of the filled tank is startedand a charge of hydrofluoric acid is added in such an amount that theresultant mixture will have the desired strength. In practice, it hasbeen found that the best limits of strength are from 10% to 40%, andowing to the fact that at a concentration of about 16% the quantity ofthe product is much greater, while its decolorizing power is not greatlylessened, it is very vadvantageous to work with a solution of about 16%.'Ihe agitation of the mixture is continued for some time and usuallyuntil the desired reaction is completed.

. From the mixing tank, the mixture of liquid and solid materials ispumped to a suitable Washing and separating apparatus which, in thepresent example, comprises a series of the settling tanks indicated,that is to say, conical tanks, each of which has a bottom discharge anda cylinder 0r cylinders surrounding the inlet at the center of the upperportion. In the present example., three such tanks are shown, asindicated at I, I, I2. The discharge Outlets of the mixingtanks F, F2are connected .to a pipe f, and controlled by valves f2, f3,respectively. To one end of the pipe f is connected the suction side ofa pump H, Whose discharge end is connected to a pipe L leading to thelcenter of the upper portion of the washing tank I, the bottom of whichis connected through a pump K, and a pipe c to the top of the next tankI, which in turn has its bottom connected by ay pump K and pipe c to thetop of the third tank I2. The botto-m of the latter tank is connected bya pipe c2 to a filter device of any desired type, as in.- dicated at L.The pipe k2 is controlled by a suitable valve, as indicated at 7c3.

The tanks I, I, I2 are arranged at progressively higher elevations inthe order named, and each has an overfiow at z', 77, and 2. The overflow2 leads to the center of the next tankI, and the overflow z" leads tothe center of the tank I. The overflow from the tank I leads to a filterdevice M. The

center of the tank I2 is supplied continuously with Wash-water through apipe is, controlled by a suitable valve 2.

From the filter M the filtrate passes to apparatus for the recovery ofhydrofluoric acid. In the present example, this comprises aprecipitating tank N, a crystallizing boiler O, a second filter P, asuitable furnace, as, for example, the reverberatory furnace Q, andabsorption tower R.

The filter M is arranged to discharge its filtrate through a pipe m tothe precipitating tank N, which has a61 perforated false bottom, asshown.` The tank is provided with an outlet for the precipitates,controlled by a valve n, and also has a liquid discharge leading frombelow the filter bottom of the tank N, as indicated at n', wherebyliquid may be drawn from the precipitate. The liquid discharge connectswith the upper part of the boiler O and is controlled by a valve n2.rIhe boiler O has a;clischarge outlet 0 leading from its. bottom-'to thetop of the filter P, and controlledffby a valve. 0. The filter P has aliquid discharge p through which the filtrate or liquid is wasted, andalso has a discharge for solids, indicated at p', arranged to be closedin any suitable way. g

The furnace Q has va discharge pipe arg ranged to lead gases to theabsorption tower R, which is of anyv usual construction. rI`he acid isled from the tower to suitable storage tanks through a discharge conduit7'.

In the usual practice, the contents of a mixing tank, after thecompletion of the reaction, is pumped to the first tank I, where thefirst Washing and first settlement of solids occurs. The thicker mixtureis pumped from the bottom of tank I to the top of tank I, in which aafurther washing and further settlement takes place. From this tank thethickened mixture is pumped to the top of the tank I2, when the finalwashing and settling take place. With the valve 7c3 open, the'thickenedmixture is continuously discharged tothe filter L where the solids areseparated from the wash-liquid and are ready for the market.

The wash-water is continuously supplied vina regulated quantity to thetank I2, and

by means of the overfiows from each tank to the next adjacent one, acounterflow of liquid takes place with a final overflow at a regulatedrate to the-,filter M. This-filter serves to separate out small amountsof fine solids which may have floated ofi" with the overflow from thetank I. rlhe filtrate is led to the precipitating tank N, where aluminumoXid (A1203) is added in sufiicient quantity to precipitate silica(SiO2) and other impurities. The supernatant liquid is decanted ofi?l tothe crystallizing boiler, where it is heated 'under pressure, with the=result that the aluminum fluorid (Allis) crystallizes.

' From this boiler, the entire contents are discharged to the filter,which separates the crystalline mass from the liquid, the latter beingwasted, while the solids removed from time` to time are charged into thereverberatory furnace, and the hydrofluoric acid driven ofi' as a gaswhich is absorbed in the absorption tower by av suitable flow of water,the solution of HF thus obtained being drawn off at the bottom of thetower.

Instead of recovering the hydrofluoric acid in the well known mannerhereinbefore described, other suitablemethods may be ernployed. Forexample, the filtrate from thev on a scale which is intended to indicatethe percentage of color removedf by theproduet.

In the determination of this scale, a very dark solution of lowest gradePorto Rican sugar (45 Brix) was employed as the standard. A sampleofthis was subjected to the decolorizing action of about-5% of the newproduct, and then this partly decolorizedv tested with the same solutionand in the same percentage, gave a value of 69,-s0 that the figuresgiven in this specification as to the decolorizing power of the newproduct are on a scale comparable-with bone-black at 69.

What is claimed is:

1. The process of making a material lhav- A i ing decolorizingproperties, whichconsists in acting upon a carbonaceous residue of anindustrial carbonizing process with hydrofluoric acid, and thenrecovering the solids.

2. The process of making'a material having decolorizing properties,which consists in acting with hydrofiuoric acid upon a starting materialcomprising silica and a carbonaceous material obtained from anindustrial carbonizing process, and then recovering the solids. 3. Theprocess which consists in subjecting a residue of shale distillation tothe action of hydrofluoric acid.

4. The process of'makinga material having decolori-zing properties,which consists in subjecting the carbonaceous residue of an industrialcarbonizing process to the action of dilute hydrofluoric acid, andv thenrecovering the solids.

5. The process of making a material having decolorizing properties,which consists in subjecting a starting material comprising silica and acarbonaceous material obtained from an industria-l carbonizing processto the action of dilute hydrofluoric acid, and then recovering thesolids.

6. The process which' consists in subjecting a residue from shaledistillation to the action of dilute hydrofluoric acid.

7. The process which consists in subjecting an inorganic residue ofshale distillation to the action of hydrofloric acid and then washingthe solids of the reaction.

In testimony whereof, I have hereunto set my hand"i ROBERT M. .CA'ILIN

